The U.S. Army had a problem, a big problem: 165,000 gallons of some of the deadliest war materials known to man, including napalm, chlorine gas, mustard gas and sarin, a nerve gas developed by the Nazis, tiny doses of which can kill in minutes. After stockpiling these weapons of destruction for decades in its Rocky Mountain Arsenal near Denver, the government decided the time had come to dispose of the hazardous wastes but didn’t know how.

The solution? In l961, authorities drilled a well 12,000 feet deep, far below any aquifer, and over the next five years pumped hundreds of thousands of gallons of toxic wastes into a cavity in the rock miles beneath the surface.

One problem: Not long after the pumping began, Denver and nearby suburbs began to experience swarms of earthquakes. Most of them were quite small, less than 3 in magnitude, but in a region that rarely experiences earthquakes, 1,300 earthquakes in four years raised questions. Then, in August 1967, a significant earthquake — magnitude 5.3 — shook the city of Denver and the nearby suburb of Commerce, with damages that totaled over $1 million.

The Army stopped pumping the toxic wastes into the injection well. Geologists discovered the liquids had been pumped into an existing fault deep in the “basement” rock. The fault had begun to lose strength and slip, even after the pumping stopped

For city officials, this was alarming, but geologists were intrigued to discover it was possible to trigger earthquakes along existing fault lines, and a team of scientists from the U.S. Geological Survey soon launched into an experiment in an oil field with known earthquake faults in Rangely, Colo. The goal? To learn what volume of fluid pressures were required to trigger earthquakes, and to see if seismic activity could be stimulated and then brought to a halt. The experiment worked, on a small scale, and encouraging results were reported in the journal Science in March of 1976.


Oil deposits often collect around faults,
such as these depicted in the Silverthread oil field in Upper Ojai.
Graphic from Division of Oil, Gas, and Geothermal Resources.

“We may ultimately be able to control the timing and size of major earthquakes,” the team, led by C.B. Raleigh and J.H. Healy, speculated. They suggested drilling wells along the San Andreas Fault, and injecting water to release seismic pressures with little earthquakes. They hoped in this way to prevent the legendary “Big One,” an earthquake comparable to the massive and ruinous l906 San Francisco earthquake, which has a 3 percent to 30 percent chance of occurring in the next 30 years in California.

 “They actually proposed this idea, to drill wells and pump in water and trigger small earthquakes along the San Andreas,” said William Bilodeau, who chairs the geology department at California Lutheran University in Thousand Oaks. “And they got fairly far along in the planning process and then people began to say, ‘Wait a minute — what happens if we set off a really big earthquake? What’s the [legal] liability?’ ”


Fracking near faults in Ventura County

At the Oil Museum in Santa Paula, a current exhibit on hydraulic fracturing, or fracking, backed by an industry group, explains how the process works to release hydrocarbons from “tight” rock formations with high pressure blasts of water, sand and chemicals. The exhibit declares that fracking is safe, but doesn’t once mention the need to dispose of mineralized water deposits brought up from underground by fracking. In this way, the exhibit parallels what industry advocates and supporters say about fracking and don’t say about oil field disposal wells.

Sandra Burkhardt, who speaks for the oil companies in the Western States Petroleum Association, a petroleum trade group, in a presentation in May to the Santa Paula Chamber of Commerce said that “The science doesn’t support the idea that fracking causes earthquakes.”

At a meeting of the Air Pollution Control District at the Ventura County Government Center, Peter Foy, a county supervisor from Simi Valley, declared on June 11 that “There is no history of fracking ever causing an earthquake, ever.”

This omission of disposal wells misleads. In a 1990s report to the Environmental Protection Agency on injection of fluids from fracking operations, Craig Nicholson, a geophysicist and researcher at U.C., Santa Barbara, found examples of earthquakes set off by the injection of fluids in Colorado, Texas, New Mexico, Nebraska and Ohio, among other locations. He said in an interview that fracking, by its nature, generates “micro” earthquakes of low magnitude as it fractures the rock. Of greater concern when it comes to earthquakes are disposal wells. Fracking brings large volumes of “produced water” — salty water trapped in the rock underground — to the surface, which is typically separated from oil products and reinjected into underground cavities or porous rock formations. Fracking itself may not set off large earthquakes, but the injection of fluids from fracked wells can, especially when the fluids from many wells are collected and injected.

“It’s fairly clearly established that when you inject large volumes of fluid into the ground, you can trigger an earthquake if it’s along a fault,” Nicholson said. “In the field we make a distinction between inducing an earthquake and triggering an earthquake that would otherwise naturally occur sooner or later.”


Monterey shale graphic from DOGGR shows fault zones, oil fields and aquifers.

In other words, although fracking does induce or “cause” tiny earthquakes, the small volumes of fluid involved are unlikely to trigger a bigger quake. But the injection of large amounts of fluids, especially into disposal wells that concentrate fluids from numerous different wells, can trigger large earthquakes. The question of safety arises in Ventura County because our area has many well-known earthquake faults and because the county is in the midst of a well-documented oil boom.

Oil companies are buying land and mineral rights in Ventura County, encouraged by a 2012 report from the U.S. Energy Information Agency revealing that beneath much of the Central Valley and the Central Coast is a huge oil deposit called the Monterey Shale. The agency reported that this formation has more than 15.4 billion barrels of oil. Now, with fracking and other “well enhancement” techniques such as acidization, this oil can be accessed and produced. 

According to a front-page story by Timm Herdt in the Ventura County Star in April, Vintage Petroleum, a subsidiary of Occidental Petroleum, has purchased hundreds of leases in the Santa Paula and Fillmore area in the last six months, investing millions of dollars, and snapping up rights to more than 9,000 acres.

 “We do have this Monterey Shale formation in our county,” said Supervisor Linda Parks, District 2, “And we are looking at a potential oil boom, because now the industry has these new techniques for oil extraction that they didn’t have previously, including the acidizing of wells.”

Acidizing rock uses less water than “frack jobs” back East — between 10,000 and 100,000 gallons, according to petroleum engineers — but replaces the water with between 3 percent and 25 percent of hydrochloric acid. Industry advocates insist these techniques are safe, but Ventura County has seen what can happen when oil wells go wrong, especially in an earthquake.


Well failure and fault failures

In 2006, in Upper Ojai not far from Summit Elementary School, on Feb. 24, an old well blew out and began spewing huge volumes of fluids to the surface. The blowout could not be “killed” — brought under control — for three months. The incident was not reported to the nearby school or to the press, but the Division of Oil, Gas and Geothermal Resources (DOGGR) did report it to the state’s Office of Emergency Services, which reported it to other agencies, according to California Department of Fish and Wildlife records.

Alexia Retallack, of Fish and Wildlife, was surprised to hear that the blow out took three months to bring under control, but said that if the fluids — which were brine water with some light and heavy oils, according to her records — were contained to the property and did not impact state water supplies, the oil company fulfilled its responsibilities to her department, despite the fact that thousands of gallons of fluids boiled up from the broken casing. An international team of blow out experts, called Boots and Coots, now a Halliburton subsidiary, was flown in from the Middle East to plug the blow out, which cost at least $4 million.

Looking at the 76-page well report compiled by DOGGR on the blow out on Ojai #36, petroleum engineer Tom Williams called the three-month battle to control the well “very messy,” pointing out that the well casing broke off below 3,000 feet. Ultimately, the well was abandoned completely.

 “They were having a hell of a time,” he said. “You can’t really tell what is going on from the report, which includes no diagrams and is totally inadequate, but they were redrilling and sidetracking and deepening — they just had a whole bunch of problems with that well.”

Paul Hofmeister, a landowner and contractor in Upper Ojai, said that his team dug a holding pond for the blowout, which DOGGR estimated to be 9,000 gallons. He said the blowout immediately followed a nearby earthquake, and brought “brine water [that] had some oil and gas in it” to the surface at 700-900 pounds per square inch.

DOGGR records show that a 3.1 magnitude earthquake on the San Cayetano fault occurred at noon on that day, about nine miles northwest of Fillmore, at about nine miles below the surface.  

Injection wells: Earthquake and pollution

Extracting oil near an earthquake fault and through a major aquifer in Upper Ojai that supplies groundwater to Ojai and Santa Paula alarms many locals, including Michael Shapiro, a filmmaker and activist who led the successful effort to prevent the multinational Waste Management corporation from building a dump in Weldon Canyon near Ojai. In May, Shapiro told a planning division hearing at the government center:

“The San Cayetano Fault runs for about 45 kilometers right through the heart of the oil fields in Upper Ojai,” he said. “This is a major fault with a slip rate of between 1.3 and 9 millimeters a year. Scientists don’t know when it’s going to fail, but it’s not a matter of if the big one will come, but when. This fault is capable of an earthquake from between 6.5 and 7.3 in magnitude, and that ups the ante of required scrutiny, so that we don’t have one of those perfect-storm catastrophes.”

A U.S. Geological Survey of California faults, published in 2008, estimated that the San Cayetano was the sixth most active in the state, capable of producing an earthquake greater than 7 in magnitude, with an 8 percent chance of failure in the next 30 years.

Despite Shapiro’s testimony, and the testimony of many other locals and experts, the planning division nonetheless approved a permit for small local oil company, Mirada, to drill wells in the Silverthread oil field near the San Cayetano fault, in part because the company promised not to frack.

Parks continues to call for tighter regulation.

 “I think the most important thing is to protect the drinking water for the west county,” she said. “[The state agency] DOGGR has reported hundreds of spills from oil companies over just the last 10 years in Ventura County. If we can ensure safety by requiring the use of less toxic chemicals, or protect the aquifers by taking a stronger role, we should do that.”


Complex geology of Monterey shale puts oil fields
and earthquake faults not far from groundwater aquifers.

Parks acknowledges that the county government agencies don’t want to step on the toes of state agencies such as DOGGR, and are waiting for action from the state, which currently does not regulate fracking. Besides keeping records of oil operations, DOGGR also oversees injection wells for the risk of water pollution, under an agreement with the Environmental Protection Administration.

A review of DOGGR’s oversight by the EPA in 2011 was critical of DOGGR for lax enforcement of injection well standards. A consultant for the EPA, James Walker, challenged DOGGR’s Division 2, which oversees Ventura County oil production, for failing to protect groundwater from pollution from old or idle wells.

 “In our view, underground sources of drinking water are not adequately protected in idle wells,” Walker wrote. Walker said the agency let old wells with casing not cemented to modern standards remain in operation, potentially allowing the mixing of oil or gas with groundwater. Oil companies can pay as little as a $100 a year to leave a well idle.

The division oversees 1,010 injection wells in the county, of which 423 are idle. According to records from DOGGR cited in the report, there have been three instances of wells “shut in” for violating pressure standards from 2005 to 2010, but none for pollution violations.

 “The District may need to put more of an emphasis on enforcement,” wrote Walker for the EPA.

The EPA also asked the Ventura County division about public hearings on oil well issues.  Division 2 of DOGGR replied that “No public hearing has ever been conducted in this District.”

Meanwhile, in March, the Anterra Corporation, a waste management firm that serves oil companies, proposed to drill a new Class II injection well on county property closer to fracking sites being developed in Santa Paula and Fillmore, according to county planning documents.

Parks let her opposition to the idea be known.

“I want to make sure we are not polluting our surface or groundwater,” Parks said. “I don’t think it’s appropriate to use county land as a dispensary for what could be pollution.”

A representative for Anterra in Santa Paula would not comment.

Fran Pavley, a state senator whose district includes Thousand Oaks, proposes to protect groundwater and regulate fracking with a bill, SB 4, intended to provide greater transparency than is offered by DOGGR, which works closely with the oil industry. Although the fate of her bill remains uncertain, Pavley argues that she has worked collaboratively with industry, regulators and environmentalists, and says the alternative to her comprehensive bill could be even worse for the industry.

“Several counties in the state are looking at regulating the practice of hydraulic fracturing,” she said. “I’ve told the oil companies directly to their face that if the public doesn’t feel that the regulations are adequate, than there’s going to be a tremendous outcry.”

According to an USC/Los Angeles Times poll published in June, about three in five California residents oppose fracking through aquifers. Despite the concern, Gov. Jerry Brown has not taken a position on the bill or on the regulation of fracking.

Fear of fracking — and earthquakes

Geologists interviewed for this story, including Bilodeau of CLU, Craig Nicholson of UCSB, and Thomas Rockwell of the State University of San Diego, did not dismiss the risk of disposing of fluids generated by oil wells in fault zones, but all stressed the already high risk of earthquakes in Ventura County.

“The whole region of the Ventura basin is shortening in a north-south direction by nearly 1 centimeter a year, which is very significant,” said Rockwell, who wrote his dissertation on Upper Ojai geology. “You wouldn’t think that would be much, but over a thousand years, that means almost 30 feet of shortening needs to occur, and if this occurs in one large failure, that will result in a major earthquake.”

Bilodeau points to a 2011 paper that maps a fault that runs directly under Ventura Avenue, and is now believed to link up with four others. “Linkage of the Ventura/Pitas Point fault could generate a magnitude 7.3 earthquake, while rupture in association with other regional faults could produce even larger events,” concluded a team of five geologists, including James Dolan of USC. A magnitude 7.3 earthquake would release the energy of exploding about 1.3 million tons of TNT, which is roughly a thousand times the energy released by the A-bomb dropped on Hiroshima.

Nicholson said that one of the faults that extends into the Ventura basin failed in the 1994 Northridge earthquake. That quake, assessed at a 6.7 magnitude, killed 57 people, injured 8,700, and caused $40 billion in damage, making it one of the worst natural disasters of the 20th century.

“If there was no oil production at all, you would still have major damaging earthquakes in Ventura County,” Nicholson said. “That’s why it’s difficult to separate out the potential for an even higher level of earthquake risk. Oil production has been going on in Ventura County since the turn of the century and there are no indications that the amount of earthquakes has increased in this time. All geologists are saying is that you do have to be careful, and if you’re an oil company and you drill into a large fault and start pumping large volumes of fluid into that fault, then all bets are off."